A conventional solar cell for transforming light energy into electrical energy comprises a thin disc shaped crystal wafer of photovoltaic material, such as silicon, the back face of which is covered with an electrical conductive coating, and the front face of which is provided with a grid of electrical conducting material for collecting and conducting the electrical current generated from light impinging on the front face.
In a typical process of manufacturing such cell, all or a portion of the following steps may be involved:
1. Grow crystal in generally cylindrical form. PA0 2. Machine to a right circular cylinder. PA0 3. Saw cylinder into circular disc shaped wafers of desired uniform thickness. PA0 4. Etch and clean. PA0 5. Acid soak. PA0 6. Apply diffusant. PA0 7. Bake. PA0 8. Diffuse (900.degree. C. typ.) PA0 9. Oxide etch both faces. PA0 10. Etch back face. PA0 11. Apply electrical conductive material to entire back face (Print, vapor deposition, or electrical plate). PA0 12. Bake (150.degree. C typ). PA0 13. Apply grid to front face (process as in 11). PA0 14. Bake (150.degree. C typ). PA0 15. Fire (600.degree. C typ). PA0 16. Test surface resistance and sort. PA0 17. Arrange a plurality of cells in desired configuration of a module and connect the back faces and grids with wires soldered to same. PA0 18. Arrange soldered module on face of insulated supporting base and secure thereto. (Such as by a cement). PA0 19. Attach terminals of module by solder. PA0 20. Test module. PA0 21. Apply coating and sealant for protection against environment. PA0 22. Assemble modules into an array for desired electrical output by suitable wires and soldering thereof. PA0 23. Test.
As will be apparent from the foregoing, each cell is subjected to individual process treatment through step 16. Subsequent to step 16, at which point the individual cells are assembled into modules, tedious manual operations, involving soldered lead wires are involved, and, as will be apparent, further tedious and time consuming manual operations are reqired to assemble the modules into an array.